Skate boards having front and rear sets of wheels or rollers are well known and widely used. An inherent disadvantage of these prior art skate boards is the fact that they can only be satisfactorily used on hard, relatively smooth surfaces such, for example as those found on concrete, wood and blacktop. However, there are many places where such surfaces are not readily available, particularly in the winter, yet many of these places do have many natural ice surfaces during the winter. Moreover, there are many indoor ice rinks which are sufficiently large to be suitable for skate boarding provided that a satisfactory skating surface is available.
In accordance with the present invention there is provided a novel skate board adapted for use on natural or artificial ice surfaces. This skate board utilizes two pairs of blades or runners respectively disposed at the front and rear of the board. The blades in each pair are pivotable about a horizontal axis extending transversely of the board, and one pair of blades is sharper than the other pair so that one pair tends to dig into the ice surface while the other pair may slide laterally to effect maneuvering of the skate board. The sharper pair of blades is located at the end of the board from which steering is to take place. For example, for front end steering where the user's weight is toward the front, the front blades may be V-shaped in cross-section while the rear blades may be hollow ground thus permitting the rear end of the board to slide laterally and thus to pivot around the front end. We have found, however, that both sets of blades must have some degree of sharpness since the skate board will otherwise lack stability. Moreover, for ease of maneuverability the blade edges should be convex from front to rear so that only about 1 to 2 inches of the blade rests on the ice during normal use. On a 3 inch long blade a radius of 20 inches provides a satisfactory edge.
We have also found that the optimum blade edge configuration varies with different ice surface conditions and also with the desired maneuverability of the skate board. Therefore, in accordance with another feature of the invention each blade member is provided with two different easily selected edge configurations, thereby enabling a quick and easy change of the blade edges in the field.
In accordance with another feature of the invention the blade assemblies are interchangeable with the rollers on conventional skate boards whereby existing roller type skate boards are readily convertible to blade type skate boards for use on ice.